Using Cascading Style Sheets

As you already know, all the browsers interpret HTML, javascript and CSS the same way. But not always...
For CSS, there is at least a page of tests Compatibility, Quirks/Strict Mode, CSS hacks, Conditional comments... using a cascade style sheet dealing with almost all known problems (IE, NN, Opera...), a page with CSS tests and cross-browser solutions CSS hacks, floats, popups, containers, margins, centering, layouts..., a "Full CSS Property Compatibility Chart CSS1, CSS2 and Internet Explorer CSS extensions and grades the level of support" and bugs pages.

This page uses cascade style sheets.
It does not use the tag <table>.

Its menu on the left only uses CSS and is browser dependent.

Any recent browser should be able to read it.
A Braille or vocal navigator can read this "tableless" page more easily.
It should adapt to the screen settings although proportional fonts generate alignment problems.

Actually, it has been modified since I installed the last versions of MSIE 6 (6 SP1 - in 2002) and Netscape 7.0 as many rules do not accept the same declarations (p:first-letter for example with MSIE 6) and as Netscape does not accept some multi-column rules, a part of the site was rewritten with tables.
You can test your browser computing problems by modifying the text size (View / text size, View /Zoom, Ctrl +, ...).
A few compatibility problems are listed in the page about browsers.
If you are interested, a way to build a simple no-javascript and tableless stylesheet, CSS information to make pages compatible with recent browsers and recent solutions are also online.

The other version of the site has an older style sheet which is safer (a style sheet replacing the proportional size of table cells by fixed ones would have been better).

This page uses two or four cascade style sheets after the browser detection (one stylesheet can do the job and detection should be avoided).
For the default style:
style_old_nn4.css for a possible compatibility with Netscape 4 and the pages partially converted.
style2.css for the last versions - the instructions here freeze or crash old navigators. Actually, since optional closing tags have been added (in 2002), NN4 doesn't crash anymore. Only display fixes are still there.
style2ie.css if you use MSIE 5, 5.5 or 6.
style2ie5.5.css if you use MSIE 5 or 5.5 to fix the problems with the tag <p> and the box model.
not_msie.css if your browser is really CSS compliant.
Then a style for a browser problem or advantage is added.
Another style sheet would be necessary for Opera 5 to fix the alignment and font problems.
Piling style sheets - which should be avoided - leads far away from the goal of CSS: simplifying the layout design of a website.
A few hacks, filters or guidelines could lead to only two style sheets.
Using dynamic CSS - other unadvisable method - can even reduce the list to one stylesheet.
This page exists with only two style sheets.
It also exists with one style sheet, but Netscape 4 won't display it correctly.

If you use Mozilla or Firefox, you can switch to the experimental alternate style sheets provided.
If your browser accepts cookies and sends the original referrer ("HTTP_REFERER"), you can test the two style sheets (and a CSS popup) under the menu on the left.

Thus, the browser identifier will affect the source and a website mirror.

Here are the most useful style components with a few comments:

Here is the structure of the HTML page before the inclusion of the menus in a javascript file for recent browsers:

As the style sheets (style_old_nn4.css, style2.css) have evolved a lot, you can find them as well as the javascript files in the Internet Explorer cache or by mirroring the site.
You can read much better explanations at The CSS Know-How Site, tutorial - look ma! no tables, CSS Creator, css /edge or A list apart.
If you are interested, you can have a look at a way to build a no-javascript and tableless stylesheet with most web browsers or recent browsers.
For CSS templates known to work in Netscape 4.x, have a look there:

In the current version in PHP (more or less debugged), the site still uses the same style sheets and much less javascript.

If you want a program to create or test style sheets, try TopStyle Lite for Windows or cssed for Linux.
To find out the syntax errors in your stylesheets, you can use the markup validation service of the W3C.
To debug these stylesheets, the most convenient tools with Firefox or Mozilla are the extensions "Web Developer" and Firebug.

You can test your stylesheets locally with the standalone versions of Internet Explorer 5.01, 5.5 and 6 you can download from the website tredosoft although there are a few restrictions or with the Internet Explorer Collection (Internet Explorer 5.01, 5.5, 7 and 8).

With javascript

tableless pages